The known means for measuring liquid supply—e.g., water, oil etc.—is a mechanical apparatus since the electronic existing apparatus is inaccurate. Therefore, irrigation systems are usually based on time of supplying water instead of quantities of water. The main disadvantage of this method is being inaccurate. The quantity of supplied water during the time sequence depends on the pressure of the supplied water and moreover in case of a broken pipe much water can be wasted since the quantity of water dose not control. The present invention provides an accurate liquid supply measuring apparatus, based on electrical method that is capable to supply its own electrical consumption.